Not applicable.
Not applicable.
Not applicable.
This invention relates to a container closure which can be screwed on and off.
A variety of packages that include closures or lids on containers have been developed for household products, personal care products, and other products. One type of package includes a container that is threaded around the container mouth or opening and includes a closure with a skirt having mating threads for threadingly engaging the container threads. It would be desirable to provide an improved closure for use with such packages.
Additionally, it would be advantageous if such an improved closure could incorporate a structure which could be more easily grasped by the user""s fingers for opening the closure. It would be desirable in some applications to provide a closure which includes a structure in part of the closure that includes a color, texture, or material that is different from the color, texture, or material in the rest of the closure. In some applications, it may be especially desirable if part of a closure could be provided with such a structure made of material that is softer and/or less slippery than the rest of the closure or which otherwise feels different, or provides a different tactile sensation, than the rest of the closure. Preferably, such a structure should provide improved frictional engagement with the user""s fingers under wet conditions so as to minimize the tendency of the finger to slip off of the closure. Preferably, such an improved closure should also desirably facilitate the removal or installation of the closure by a child as well as by an elderly person having impaired manual dexterity or reduced strength.
It would also be beneficial if such an improved closure could also accommodate, or actually contain, features which provide good sealing of the closure to the container by accommodating imperfections in the container finish.
It would also be advantageous if such an improved closure could accommodate a variety of aesthetically pleasing designs adaptable for use on various containers.
It would also be beneficial if such an improved closure could readily accommodate its manufacture from a variety of different materials.
Further, it would be desirable if such an improved closure could be provided with a design that would accommodate efficient, high quality, large volume manufacturing techniques with a reduced product reject rate.
Preferably, the improved closure should also accommodate high speed manufacturing techniques that produce closures having consistent operating characteristics unit-to-unit with high reliability.
The present invention provides an improved closure which can accommodate designs having the above-discussed benefits and features.
According to one aspect of the present invention, a closure is provided for an opening to a container. The closure is especially suitable for use on a large or wide mouth container that contains a typical household product, such as a comestible product, personal care product, cleaning product, etc.
The closure is adapted for movement between a closed position occluding the opening and an open position spaced from the opening. The closure includes a body for being mounted to the container. The body comprises a first, generally rigid piece, which is molded from a material. The first piece may advantageously be molded from polypropylene which is generally rigid in its after-molded, completed condition.
A second piece is molded from a material onto the first, rigid piece and bonded to the first, rigid piece to define a portion of the periphery of the exterior of the closure. In a presently preferred embodiment, the second piece which defines a portion of the periphery of the exterior of the closure is molded from a rubber based, thermoplastic elastomer which is softer to the touch than is the material from which the first piece is molded. The second piece may advantageously have a different color than the first piece.
In a presently contemplated preferred form, the closure of the present invention is not connected to the container by a hinge and is adapted to be threadingly engaged with the container.
Further, it is presently contemplated that a preferred form of making the dispensing closure includes bi-injection molding techniques, although other molding techniques could be employed, such as two-shot molding, multi-injection molding, or over-molding. In general, the closure is made by injecting a first material, such as polypropylene, into the vacant cavity of an injection molding tool. During the first injection, part of the cavity is blocked to prevent the melt (e.g., the hot, flowable polypropylene) from filling certain regions of the cavity. The first material is then allowed to cool briefly. Subsequently, the blocking component or components are removed from the molding tool to expose the additional region or regions of the cavity volume. A second injection of thermoplastic material is then effected, typically with a different thermoplastic material than the first material. The second injection of the thermoplastic material fills the remaining, vacant region or regions of the cavity and bonds to the substrate material of the first injection.
The improved closure can be readily designed to provide an improved peripheral top surface region for being gripped by the user""s fingers. The peripheral surface region may be softer than the rest of the closure and/or may provide increased friction to prevent slippage between the user""s fingers and the closure. The peripheral surface region can also be readily provided with a different color, as well as a different texture or material, than the rest of the closure.
The improved closure can also be readily designed to provide a seal within the closure for sealing against the container around the container opening, and the seal can be composed of a material, and provided with a configuration, that accommodates imperfections in the container finish so as to provide good sealing notwithstanding such imperfections.
Numerous other advantages and features of the present invention will become readily apparent from the following detailed description of the invention, from the claims, and from the accompanying drawings.